Shell colour diversification induced by ecological release: A shift in natural selection after a migration event

Ecological release is often attributed to the rapid adaptive diversification of phenotypic traits. However, it is not well understood how natural selection changes its strength and direction through the process of ecological release. Herein, we demonstrated how shell colour of the Japanese land snail Euhadra peliomphala simodae has diversified via a shift in natural selection due to ecological release after migration from the mainland to an island. This snail''s shell colour diversified on the island due to disruptive selection after migration from the mainland. We used trail camera traps to identify the cause of natural selection on both the mainland and the island. We then conducted a mark–recapture experiment while collecting microhabitat use data. In total, we captured and marked around 1,700 snails on the mainland, some of which were preyed upon by an unknown predator. The trail camera traps showed that the predator is the large Japanese field mouse Apodemus speciosus, and the predatory frequency was higher on the mainland than on the island. However, this predation did not correlate with shell colour. Microhabitat use on the island was more extensive than on the mainland, with snails on the island using both ground and arboreal microhabitats. A Bayesian estimation showed that the stabilizing selection on shell colour came from factors other than predation. Our results suggest that the course of natural selection was modified due to ecological release after migration from the mainland, explaining one cause of the phenotypic diversification.     

Tracheal motile cilia in mice require CAMSAP3 for the formation of central microtubule pair and coordinated beating

Motile cilia of multiciliated epithelial cells undergo synchronized beating to produce fluid flow along the luminal surface of various organs. Each motile cilium consists of an axoneme and a basal body (BB), which are linked by a “transition zone” (TZ). The axoneme exhibits a characteristic 9+2 microtubule arrangement important for ciliary motion, but how this microtubule system is generated is not yet fully understood. Here we show that calmodulin-regulated spectrin-associated protein 3 (CAMSAP3), a protein that can stabilize the minus-end of a microtubule, concentrates at multiple sites of the cilium–BB complex, including the upper region of the TZ or the axonemal basal plate (BP) where the central pair of microtubules (CP) initiates. CAMSAP3 dysfunction resulted in loss of the CP and partial distortion of the BP, as well as the failure of multicilia to undergo synchronized beating. These findings suggest that CAMSAP3 plays pivotal roles in the formation or stabilization of the CP by localizing at the basal region of the axoneme and thereby supports the coordinated motion of multicilia in airway epithelial cells.     

Osteoclasts adapt to physioxia perturbation through DNA demethylation

Oxygen plays an important role in diverse biological processes. However, since quantitation of the partial pressure of cellular oxygen in vivo is challenging, the extent of oxygen perturbation in situ and its cellular response remains underexplored. Using two‐photon phosphorescence lifetime imaging microscopy, we determine the physiological range of oxygen tension in osteoclasts of live mice. We find that oxygen tension ranges from 17.4 to 36.4 mmHg, under hypoxic and normoxic conditions, respectively. Physiological normoxia thus corresponds to 5% and hypoxia to 2% oxygen in osteoclasts. Hypoxia in this range severely limits osteoclastogenesis, independent of energy metabolism and hypoxia‐inducible factor activity. We observe that hypoxia decreases ten‐eleven translocation (TET) activity. Tet2/3 cooperatively induces Prdm1 expression via oxygen‐dependent DNA demethylation, which in turn activates NFATc1 required for osteoclastogenesis. Taken together, our results reveal that TET enzymes, acting as functional oxygen sensors, regulate osteoclastogenesis within the physiological range of oxygen tension, thus opening new avenues for research on in vivo response to oxygen perturbation.     

Analysis of microbiota involved in the aged natural fermentation of indigo

Although the indigo reduction process is performed via natural fermentation and maintained under open-air condition, the indigo-reducing reactions continue for 6 months (on average) or longer. Identifying the mechanism underlying the maintenance of this process could lead to the development of a novel, long-lasting, unsterilized bioprocesses. To determine the mechanisms underlying the maintenance of the indigo fermentation system microbiota for more than 6 months in a reduced state in an anaerobic alkaline environment, we examined changes in the microbiota in one early-phase batch and two aged batches of indigo fermentation fluid. The microbiota in the aged fermentation fluid consisted mainly of the genera Alkalibacterium, Amphibacillus, Anaerobacillus and Polygonibacillus and the family Proteinivoraceae. The genera Alkalibacterium, Amphibacillus and Polygonibacillus are known to include indigo-reducing bacteria. Although the transition speed was slower in the aged fermentation fluid than in the early-stage fluid, the microbiota in the aged fermentation fluid maintained for more than 6 months was drastically changed within a period of 3 months. The results of this study indicate that the bacterial consortia consisted of various indigo-reducing species that replace the previous group of indigo-reducing bacteria. The notable transitional changes may be concomitant with changes in the environmental conditions, such as the nutritional conditions, observed over 3 months. This flexibility may lead to important changes in the microbiota that allow for the maintenance of a fermentation-reducing state over a long period.     

Discovery and SAR of a novel series of Natriuretic Peptide Receptor-A (NPR-A) agonists

Novel thienopyrimidine compounds 2 and 3 were discovered from high-throughput screening as Natriuretic Peptide Receptor A (NPR-A) agonists. Scaffold hopping of a thienopyrimidine ring to a quinazoline ring, introduction of the basic functional group and optimization of the substituent on the 6-position of the benzene ring of quinazoline led to improved agonistic activity. We discovered compound 48, which showed potent agonistic activity for NPR-A with an EC₅₀ value of 0.073 μM, indicating 350-fold potency compared to the hit compound 3.     

Domain architecture of vasohibins required for their chaperone‐dependent unconventional extracellular release

Vasohibins (VASH1 and VASH2) are recently identified regulators of angiogenesis and cancer cell functions. They are secreted proteins without any classical secretion signal sequences, and are thought to be secreted instead via an unconventional protein secretion (UPS) pathway in a small vasohibin‐binding protein (SVBP)‐dependent manner. However, the precise mechanism of SVBP‐dependent UPS is poorly understood. In this study, we identified a novel UPS regulatory system in which essential domain architecture (VASH‐PS) of VASHs, comprising regions VASH1_91–180 and VASH2_80–169, regulate the cytosolic punctate structure formation in the absence of SVBP. We also demonstrate that SVBP form a complex with VASH1 through the VASH1_274–282 (SIa), VASH1_139‐144 (SIb), and VASH1_133–137 (SIc), leading to the dispersion in the cytosol and extracellular release of VASH1. The amino acid sequences of VASH‐SIa and VASH‐PS, containing SIb and SIc, are highly conserved among VASH family members in vertebrates, suggesting that SVBP‐dependent UPS may be common within the VASH family. This novel UPS regulatory system may open up new avenues for understanding fundamental protein secretion in vertebrates.     

Expression of Six Proteins Causes Reprogramming of Porcine Fibroblasts Into Induced Pluripotent Stem Cells With Both Active X Chromosomes

In this study, we created porcine‐induced pluripotent stem (iPS) cells with the expression of six reprogramming factors (Oct3/4, Klf4, Sox2, c‐Myc, Lin28, and Nanog). The resulting cells showed growth dependent on LIF (leukemia inhibitory factor) and expression of multiple stem cell markers. Furthermore, the iPS cells caused teratoma formation with three layers of differentiation and had both active X chromosomes (XaXa). Our iPS cells satisfied the both of important characteristics of stem cells: teratoma formation and activation of both X chromosomes. Injection of these iPS cells into morula stage embryos showed that these cells participate in the early stage of porcine embryogenesis. Furthermore, the RNA‐Seq analysis detected that expression levels of endogenous pluripotent related genes, NANOG, SOX2, ZFP42, OCT3/4, ESRRB, and ERAS were much higher in iPS with six factors than that with four reprogramming factors. We can conclude that the expression of six reprogramming factors enables the creation of porcine iPS cells, which is partially close to naive iPS state. J. Cell. Biochem. 118: 537–553, 2017. © 2016 Wiley Periodicals, Inc.     

Aryl hydrocarbon receptor signaling involved in the invasiveness of LNCaP cells

There is now mounting evidence that the aryl hydrocarbon receptor (AhR) plays an important role in physiologic responses such as development, cell cycle regulation, immune function and also malignant transformation in various tissues. The strong nuclear AhR expression is observed in the invasive phenotype, and an elevated nuclear AhR expression is associated with a poor prognosis of human prostate cancer. On the other hand, there are conflicting results that the AhR deficiency results in increased susceptibility to prostate tumors in mouse model. In the present study, we investigated AhR expression and its role in the growth and invasiveness of human prostate cancer cells. The AhR protein expression was detected in prostate cancer cell lines and human prostate cancer tissues. A small interfering RNA targeting AhR, constitutive active AhR expression vector, and AhR agonist and antagonist were used to moderate its expression and signaling. The induction of AhR signaling attenuated invasiveness of prostate cancer cells without affecting the cellular growth rate. These results suggest that AhR signaling in prostate cancer cells facilitates invasion of these cells, and modulation with this signaling can be a potential therapeutic target of invasive tumors.     

Isolation and spectral characterization of thermally generated multi-Z-isomers of lycopene and the theoretically preferred pathway to di-Z-isomers

Lycopene has a large number of geometric isomers caused by E/Z isomerization at arbitrary sites within the 11 conjugated double bonds, offering varying characteristics related to features such as antioxidant capacity and bioavailability. However, the geometric structures of only a few lycopene Z-isomers have been thoroughly identified from natural sources. In this study, seven multi-Z-isomers of lycopene, (9Z,13′Z)-, (5Z,13Z,9′Z)-, (9Z,9′Z)-, (5Z,13′Z)-, (5Z,9′Z)-, (5Z,9Z,5′Z)-, and (5Z,9Z)-lycopene, were obtained from tomato samples by thermal isomerization, and then isolated by elaborate chromatography, and fully assigned using proton nuclear magnetic resonance. Moreover, the theoretically preferred pathway from (all-E)-lycopene to di-Z-isomers was examined with a computational approach using a Gaussian program. Fine-tuning of the HPLC separation conditions led to the discovery of novel multi-Z-isomers, and whose formation was supported by advanced theoretical calculations.     

Development and evaluation of yeast-based GFP and luciferase reporter assays for chemical-induced genotoxicity and oxidative damage

Applied Microbiology and Biotechnology - We aimed to develop the bioassays for genotixicity and/or oxidative damage using the recombinant yeast. A genotoxicity assay was developed using recombinant...